1. Field of the Invention
This invention relates to an automatic condensate draining device for compressed air systems, more particularly to an air pressure type automatic condensate draining device which can be installed at a level higher or lower than that of the accumulated condensate of the compressed air system.
2. Description of the Related Art
In a conventional compressed air system, it is necessary to provide a cooling process between successive stages because air becomes heated when compressed. Water vapor in the air entering the compressed air system leaves as a superheated vapor and is converted to condensate upon cooling. As the condensate generated by the cooling process accumulates, a condensate draining device must be installed to discharge the condensate and avoid damage to the compressed air system.
Most conventional compressed air systems usually have a manually operated release valve provided at the bottom of the gas cylinder to discharge condensate that has accumulated inside the gas tank. Thus, someone must be assigned to operate and maintain the opening and closing of the release valve to avoid damage to the compressed air system.
Other conventional compressed air systems are fitted with an automatic condensate draining device in order to obviate the need for a manually operated release valve. There are two kinds of automatic condensate draining devices available for this purpose: an electromagnetic type draining device, and the more frequently used, float ball type draining device.
FIG. 1 is an illustration of a conventional float ball type draining device. A hollow casing 100 of the condensate draining device 10 is mounted on a gas tank 20 of a compressed air system at a condensate discharge outlet 21 located at the bottom portion of the gas tank 20. A shaft 12 extends vertically downward inside the hollow casing 100. A lever 11 has a central portion hinged to the shaft 12. A float ball 13 is mounted on one end of the lever 11. A stopper 15 is provided on the other end of the lever 11 to plug the discharge opening 14 of the hollow casing 100. Water vapor converted into condensate flows from the gas tank 20 and accumulates in the hollow casing 100 via the condensate discharge outlet 21. As the condensate level inside the hollow casing 100 rises, the float ball 13 similarly rises. The lever 11 pivots about the shaft 12 to gradually move the stopper 15 away from the discharge opening 14, thereby causing condensate that has accumulated inside the hollow casing 100 to flow out of the same via the discharge opening 14.
One of the disadvantages of using the above described float ball type draining device is that it should be mounted at a level below the condensate discharge outlet of the gas tank. Since the space occupied by the condensate draining device is relatively big (approximately 20 centimeters in height), it cannot be used with conventional small compressed air systems (The space between the bottom edge of the gas tank and the ground is at approximately 10 centimeters). Furthermore, the conventional float ball draining device is of a sealed-type construction, making it difficult to remove dirt and other particles that collects therein and which may eventually block the discharge opening of the condensate draining device.